Michael G. White
Professor
B.S., 1974, University of Pittsburgh; Ph.D., 1979, University of California; Research Associate, University of British Columbia, Vancouver, Canada, 1979-80; Senior Chemist, Brookhaven National Laboratory, 1995-present; Chair, Chemistry Department, Brookhaven National Laboratory, 2000-2001; Professor, SUNY Stony Brook, 2001-present.

Phone: BNL: (631) 344-4345 USB: (631) 632-1722
E-mail: mgwhite@bnl.gov

Group Web Site: http://www.chemistry.bnl.gov/white/

PHYSICAL CHEMISTRY: DYNAMICS AT SURFACES

Our research is aimed at providing a molecular level understanding of the energetics, dynamics and morphology-dependence of elementary surface reactions that play key roles in energy-related catalysis. Specifically, we are interested in systems involving simple feedstock chemicals (e.g., H₂, CO, CO₂, O₂, CH₄), the selective oxidation of C₁ and C₂ molecules (e.g., CH₃OH, C₂H₄) and reaction systems that have environmental impact (e.g., De-NO_x, De-SO_x). We approach these problems from a chemical physics perspective in which experiments are designed to probe the adsorbate-metal potential surface and the dynamical paths that lead to reaction. Our experimental program makes extensive use of lasers for both state-selective detection of desorbed products and the photo-initiation of surface processes such as desorption, diffusion, dissociation and reaction.

Catalysis on the Nanoscale

We are investigating the size-dependent properties of metal-containing nanoparticles using gas-phase methods for cluster formation and mass selection, followed by deposition onto well-defined substrates. Our focus is on the electronic and catalytic properties of nanostructured molybdenum carbides, nitrides, sulfides and phosphides, many which are catalytically active in their bulk form (e.g., powders, thin films). Recent work in collaboration with Prof. Johnson at USB has demonstrated that laser-ablation plasma sources are capable of generating a wide range of neutral and cation Mo_nX_m(X=C, N, S) clusters species with high mass (n>30) and unusual stoichiometry. We find that the Mo₈C₁₂ and Mo₆S₄ neutral clusters are the most prominent in the carbide and sulfide mass distributions, with the former belonging to the “met-car” family of stable M₈C₁₂ clusters previously observed for other early transition metals (e.g., Ti, V, Zr). Recent theoretical calculations by Dr. Muckerman and co-workers at BNL have confirmed that the Mo₈C₁₂ cluster a caged molecule with unusual stability. Future work involves the “soft-landing” of such clusters onto well-characterized substrates for size-dependent studies of electronic and atomic structure and reactivity.